| 摘要 |
PURPOSE:To suppress temperature rise of coil low and achieve the improvement of service durability by forming through-holes in the portion communicating with the magnetic part of magnetic field part and connecting said communicating part and the portion which is subjected to the pressure change in enclosure by means of a pipe. CONSTITUTION:A through-hole 15 is provided to the back of a cabinet 13 which is mounted with a speaker at its front. A pipe 16 is connected to this through-hole 15, said pipe being connected to the bottom of the speaker 14 by passing through the back of the cabinet 13. Two through-holes 30, 31 are provided in the position in proximity to the center pole 17 of the plate 18 so as to communicate with the space 29 communicating to the magnetic gap 27 of the magnetic field part 21 of the speaker. One end of the abovementioned pipe 16 is fitted and connected into one through- hole 30. As a result, forceful air current is produced in the magnetic gap 27 and the Joule heat evolved in the coil 25 is dissipated by this air current, whereby the temperature rise of the voice coil may be suppressed. |
